The present commercial method for manufacturing organohalosilanes is well known and is described in U.S. Pat. No. 2,380,995, issued to Rochow. This method, known as the "direct process" , involves the direct reaction of an organo-halide, such as methyl chloride, with silicon particles in order to produce organochlorosilane. Intermixed with the particles of silicon are particles of copper, forming a reactive mass or a reactive contact mass. In commercial practice, the direct process is generally carried out in one of three types of equipment: the stirred bed type of reactor as described in Sellers, U.S. Pat. No. 2,449,821; the fluidized bed reactor, as described in Reed, at al., U.S. Pat. No. 2,389,931; or the rotary kiln.
At some point in the production of the organochlorosilanes by the direct process, the reactive mass or reactive contact mass containing silicon particles becomes less reactive. Thus, spent or less reactive silicon particles are removed from the reactor and new silicon particles inserted so that a continuous reaction may continue unabated or so that a batch reaction may be restarted. The spent contact mass is generally referred to as residual silicon, residual silicon powder, residual silicon-containing contact mass or residual contact mass and these terms are used interchangeably herein.
A problem with the residual silicon is that it is highly reactive and exothermic upon exposure to moisture. Thus, disposal or transportation of the residual silicon is complicated by reaction with atmospheric moisture and other sources of water to produce heat, hydrochloric acid, hydrogen gas and other products.
It is an object of the present invention to stabilize the residual silicon to permit transportation and disposal.
It is another object of the present invention to produce stable pellets of residual silicon for transportation and disposal.